This research was performed focusing on field investigations over the tropical rainforest region in Africa, especially the Zaire River Basin, so as to create a scientific ecoclimatological database for the analysis of the seasonal, inter-annual and long-term changes in both the rainforest ecosystem and the climatological parameters (rainfall, temperature, vegatation cover, etc.) over this region.Suffices to point here the main new findings from our analyzes over this tropical rainforest region and the surrounding savanna woodland and grassland areas : 1. The existence of a remarkable 2-to 5-year oscillation in the temperature data, with strong positive correlationship with the Southern Oscillation Index (SOI), and therefore the ENSO.2. An omnipresent quasi-decadal oscillation (QDO) in the temperature, humidity and rainfalls records, with a periodicity matching that of the solar activity (sunspot numbers). 3. A persistent warming trend observed at all the stations in Zaire, with a mean
… Moreincrease of 0.5 to 1.5ﾟC over the 1960-90 period : this is more than the values observed for the global warming on the same 30-year period. 4. For every analyzed point, a strong desiccation trend, manifested by a strong decrease in rainfalls as well as the lengthening of the dry season (up to 3 months at some stations). 5. The magnitude of these long term trends (warming and desiccation) suggests that these phenomena are regional and imbedded in the change in the local ecoclimatological conditions. The remarkable relationship between these changes and the local people's lifestyle and alteration of the environment for their living (shifting cultivation, bushfire, fuel wood, etc.) has been highlighted.1.2〜5年スケールの顕著な気温の振動が存在し、これはENSOと密接に関係している。2.約10年の周期的振動も存在し、太陽黒点数の変化と高い相関を示す。3.どの地点においても、全球平均の昇温率に比べてかなり高い、永年的な気温の増加(30年で約0.5〜1.5℃)が認められた。4.ほとんどの観測点で、相対湿度・降水日数・降水量が、緩やかであるが継続的に減少している。地域によっては、乾期が長くなるとともに、雨期における降水量が減少している。5.こうした長期的な気候変動(地域的な乾燥化と温暖化)と、現地の人々の生活活動(焼き畑農業、山焼き、燃料用薪等)による森林伐採との関係が明らかになった。 Less